#!/usr/local/bin/perl6

sub f($p, $q) {
    (1 - $p) + $p * (1 - $q);
}
sub g($p, $q) {
    1 - $p * $q;
}

say '==, p, q, (1 - p) + p * (1 - q), 1 - p * q';
for 0..9 -> $p {
    for 0..9 -> $q {
        my $p0 = $p / 10;
        my $q0 = $q / 10;
        my $a1 = f($p0, $q0);
        my $a2 = g($p0, $q0);
        say $a1 == $a2, ", $p0, $q0, $a1, $a2";
    }
}